Abstract

Objective:

This study aims to examine the frequency of zero end-digit in blood pressure recordings of patients in a primary care facility over a 10-year period.

Design and Method:

Data was obtained from a 10-year retrospective cohort of 1547 randomly selected patients registered with the Department of Primary Care Medicine clinic at the University of Malaya Medical Centre. Systolic and diastolic blood pressure readings in 1998, 2002 and 2007 were captured from patient records.

Results:

In 1998, 98.3% of systolic blood pressure (SBP) readings ended in zero and 93.9% of diastolic blood pressure (DBP) readings ended in zero. In 2002, zero end-digits were recorded in 95.0% of SBP and 89.6% of DBP readings. In 2007, SBP and DBP readings ending in zero were 88.7% and 87.9%, respectively.

Conclusions:

While in our study there was a reduction in end-digit preference for zero over 10 years, the prevalence of end-digit preference is still very high. Many other studies have also shown that despite numerous international guidelines defining protocols for measurement, reading and recording of blood pressure, there is still strong end-digit preference, especially for zero. This could lead to under or overestimation of blood pressure, hence affecting the diagnosis of hypertension as well as influencing antihypertensive medication prescribing patterns. The increasing use of automated sphygmomanometers may reduce the incidence of end-digit preference in blood pressure recording and this needs to be studied.